What Was the Name of Johann Sebastian Bach' Second Wife?

The name of Johann Sebastian Bach's second wife was Anna Magdalena Keul before she married. She was a well-known musician. After her wedding her name was Anna Magdalena Bach, of course. She called
herself Anna Magdalena Bachin too. That is how she signed her request to the council of Leipzig, after Johann Sebastian Bach had died in 1750. This letter from her still exists today.